Topic: CycleX CX-7 cam timing - Any experiences out there? Finally got it on all 4!

[PeWe]

I think that I finally got my cam timed....

Valve lash is an important player in this kind of game.  After plenty of settings and measurements.
Now measured on the retainer instead of valve adj screw.
My dial indicator has a very short shaft. Placed a magneto on the retainer to make it possible to measure valve lift with the short shaft without dial indicator in contact with rocker arm.

@ lift: 1.0mm (0.004")
@ valve lash: 0,1mm (~0.0004")
Total lift measured @ 0 lash. Confirmed with 0.1mm valve lash and got 9,78mm lift on intake.

                     IN                                             EX   
   open BTDC   close ABDC   open BBDC   close ATDC
       27                  57,5           53,5              22,5
Duration           264,5                        256   
Lobe center   105,25                       105,5   

Lift @ 0 lash    9,9                                       8,95   
inch                  0,390                              0,352   



EDIT: Could not resist another visit into the garage...
I had to see the final values above, now with 0 valve lash.
            
cyl 1         IN                                     EX   
   open BTDC   close ABDC   open BBDC   close ATDC
   29                   59                   56                25
Duration            268                                261   
Lobe center       105                              105,5   

Conclusion: Last values very close to my initial settings. The result almost spot on the spec must have been caused by lash.
I'll use this setting with 0.0004" valve lash (0.10mm) as specified. Not tight?
My old, "not hot" cam had specified  IN 0.0005 (0.12mm),  EX 0.0007 (0.18mm).  I used 0.15mm for both.

[PeWe]

I had to check all 4 cylinders to verify the cam and how I measure. I found that the valve lash is VERY important for the result, especially the lift. If the adj screw is not tightened enough the lift will not be correct, too low value.

The adj screw need to be tightened for 0 lash and overcome the lash and softness in the rocker arm bearing as well. Oil surfaces in rocker arm bearing and on lobes.

I got rather equal numbers on all cylinders. I'm happy with the timing and next is to see how it will work when the bike is running.


All cyl numbers attached

EDIT:
I had to make another lift measurement again. This time with even more tightened adj screw, just until I saw the retainer start to move.
Lift on cyl1  9,98mm (0,393"). (last numbers in attached pdf 9,87mm (0,389").
The lift is in my engine and valve train around 10mm, close to the spec.


Lash affecting the lift in a negative way is not only the obvious valve lash, its the entire valve train from lobe to valve with its softness and additional lash. It might need hundreds of turning the crank around manually with a socket wrench, looking at the dial indicator, degree wheel to get the feeling for it and finally find the numbers hidden in the cam.  I know now for next cam..
For me this cam fulfills its specification and my need of an upgrade from my old Action Fours SS-1 that has served me well. I'm very curious how the bike will behave.

[CBJoe]

Hey PeWe...sorry to drag this up from the distant past..but have you stuck with the CX-7 Cam numbers you came up with over the years? 

I ask because i'm in the process of helping MCRider degree his new CX=7 Cam this Sunday.  It's a learning process for me 

I'm also trying to understand the point of measuring all 4 cyliners since once you set one all should fall in line.  Is it because you were wanting to be sure you had the best happy medium between the manufacturing tolerance between all 4?

Sorry for stupid questions....I'm just trying to learn the theory to understand the process.

Cheers, Joe

[PeWe]

Hi Joe,
I measured all cylinders as a training and verify how the cam lobes looked like on all 4. I had the CX-7 cam in then, changed to other cams after that. All other cams installed by measure cyl 1 only.
Measure with 0 lash to measure the lift and cam numbers. Measure and time with running lash to see the real picture. Other guys on this forum have advanced the cam a few degrees from cam card.
Equal lobe centers (In vs Ex) is often used as I got here. Some other cams are way different.